Toad-flax Cress / Center For Plant Conservation
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Plant Profile

Toad-flax Cress (Hesperidanthus suffrutescens)

Shrubby reed-mustard grows in semi-barren, dry habitat that has fine textured soil intermixed with shale fragments (as shown here). Photo Credit: Vincent Tepedino
  • Global Rank: G1 - Critically Imperiled
  • Legal Status: Federally Endangered
  • Family: Brassicaceae
  • State: UT
  • Nature Serve ID: 146617
  • Lifeform: Subshrub, Forb/herb
  • Date Inducted in National Collection: 02/09/1992

A perennial herbaceous plant with clumped stems arising from a branching woody root crown. The flowers are light yellow or green-yellow in a raceme (cluster) at the end of the stems.

Where is Toad-flax Cress (Hesperidanthus suffrutescens) located in the wild?


This species occurs in a desert shrubland, with occasional Utah Juniper and Pinyon Pine trees. It grows on clay soils with chips of white shale. The soil is derived from the Evacuation Creek Member of the Green River geological formation between 5,400-6,000 feet elevation.


Found in the Uintah Basin in Duchesne and Uintah counties, Utah. (State of Utah Natural Resources 2002)

States & Provinces:

Toad-flax Cress can be found in Utah

Which CPC Partners conserve Toad-flax Cress (Hesperidanthus suffrutescens)?

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

Tina Stanley
  • 01/16/2024
  • Orthodox Seed Banking

Red Butte Garden has sent at least 250 wild-collected seeds of Hesperidanthus suffrutescens to the USDA-ARS National Laboratory for Genetic Resources Preservation for long term storage.

Tina Stanley
  • 01/16/2024
  • Seed Collection Orthodox Seed Banking

Between 2004 and 2007, Red Butte Garden staff made 4 wild seed collections representing 285 seeds from 22 individuals of Hesperidanthus suffrutescens. Less than 20 of these seeds are held in long term storage at Red Butte Garden.

Nature Serve Biotics
  • 05/02/2017

Endemic to semi-barren, white-shale layers in the Uinta Basin of northeastern Utah. There are currently 8 known populations with a total of about 3000 plants. The species' range and population size have declined over the past 50 years, possibly due to the quarrying of building stone and localized heavy grazing. The entire range of this species is underlain by oil-rich shale and conventional oil and gas deposits; its entire habitat is potentially threatened by energy exploration and development.

Sylvia Torti
  • 01/01/2010

Oil and gas exploration, drilling, and production Oil-shale mining and processing Off-road vehicle use and surface disturbing activities associated with energy development Building stone removal (USFWS 1994)

Sylvia Torti
  • 01/01/2010

Three known populations with a total number of individuals estimated at about 5,000 individuals. (USFWS 1994)

Sylvia Torti
  • 01/01/2010

None known.

Sylvia Torti
  • 01/01/2010

Populations of this species are partially on the Uintah-Ouray Reservation, the naval oil shale reserve administered by the Department of Energy and the rest is either Bureau of Land Management or private land. Finally, a more accurate estimation of population distribution is recommended.

Sylvia Torti
  • 01/01/2010

Successful propagation protocols must be developed and more coordination is needed between the various agencies/tribes that manage this species.

Sylvia Torti
  • 01/01/2010

Limited success with ex situ propagation. This species should be studied further in the greenhouse.


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Taxon Hesperidanthus suffrutescens
Authority (Rollins) Al-Shehbaz
Family Brassicaceae
CPC Number 2035
ITIS 23130
Duration Perennial
Common Names shrubby glaucocarpum | toad-flax cress | Uinta Basin waxfruit
Associated Scientific Names Glaucocarpum suffrutescens | Hesperidanthus suffrutescens | Thelypodium suffrutescens | Schoenocrambe suffrutescens
Distribution Found in the Uintah Basin in Duchesne and Uintah counties, Utah. (State of Utah Natural Resources 2002)
State Rank
State State Rank
Utah S1
Ecological Relationships

Common Name Name in Text Association Type Source InteractionID
Mining bees Andrena Suspected Pollinator Floral Link
Mining bees Adrena merriami Suspected Pollinator Floral Link
Mining bees Andrena prunorum Suspected Pollinator Floral Link
Mining bees Andrena walleyi Suspected Pollinator Floral Link
Sweat bees Dialictus Suspected Pollinator Floral Link
Sweat bees Dialictus perdifficilis Suspected Pollinator Floral Link
Sweat bees Dialictus sedi Suspected Pollinator Floral Link
Sweat bees Evylaeus pulveris Suspected Pollinator Floral Link
Sweat bees Halictus Suspected Pollinator Floral Link
Sweat bees Halictus rubicundus Floral Visitor Link
Sweat bees Halictus tripartitus Suspected Pollinator Floral Link
Sweat bees Lasioglossum parforbessii Floral Visitor Link
Beetles Floral Visitor Link
Syrphid flies Syrphid flies Nectar Robber Link

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